JSP验证码生成

java 代码

<%@ page
        import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%>
<%@ page import="java.io.OutputStream"%>
<%@ page pageEncoding="UTF-8"%>
<%!Color getRandColor(int fc, int bc) {
                Random random = new Random();
                if (fc > 255)
                        fc = 255;
                if (bc > 255)
                        bc = 255;
                int r = fc + random.nextInt(bc - fc);
                int g = fc + random.nextInt(bc - fc);
                int b = fc + random.nextInt(bc - fc);
                return new Color(r, g, b);
        }%>
<%
                try {
                response.setHeader("Pragma", "No-cache");
                response.setHeader("Cache-Control", "no-cache");
                response.setDateHeader("Expires", 0);
                int width = 60, height = 20;
                BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
                OutputStream os = response.getOutputStream();
                Graphics g = image.getGraphics();
                Random random = new Random();
                g.setColor(getRandColor(200, 250));
                g.fillRect(0, 0, width, height);

                g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
                g.setColor(getRandColor(160, 200));
                for (int i = 0; i < 155; i++) {
                        int x = random.nextInt(width);
                        int y = random.nextInt(height);
                        int xl = random.nextInt(12);
                        int yl = random.nextInt(12);
                        g.drawLine(x, y, x + xl, y + yl);
                }
                String sRand = "";
                for (int i = 0; i < 4; i++) {
                        String rand = String.valueOf(random.nextInt(10));
                        sRand += rand;
                        g.setColor(new Color(20 + random.nextInt(110), 20 + random
                        .nextInt(110), 20 + random.nextInt(110)));
                        g.drawString(rand, 13 * i + 6, 16);
                }
                session.setAttribute("rand", sRand);
                g.dispose();

                ImageIO.write(image, "JPEG", os);
                os.flush();
                os.close();
                os = null;
                response.flushBuffer();
                out.clear();
                out = pageContext.pushBody();
        } catch (IllegalStateException e) {
                System.out.println(e.getMessage());
                e.printStackTrace();
        }
%>

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[转载]关于23种设计模式的有趣见解 | Escape/unescape的Java实现

• 2007-03-11 16:56
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